Adhesion of silver particles on aluminum beads

The kinetics of deposition of monodispersed spherical silver particles stabilized by a surfactant, Daxad 19, on aluminum beads was studied as a function of the pH and ionic strength using the packed column technique. At low pH values,the attachment proceeded from mono- to multilayer with increased ionic strength, while at high pH the adsorbed surfactant was found to play a significant role in the attachment process, resulting in multilayer deposition only. The kinetics of removal was followed by rinsing the column loaded with silver with a solution of the same composition as that of the suspension used in the deposition process. The results suggest a possible bond formation between the beads and the stabilizer adsorbed on the particles. In order to interpret the adhesion data, a uniform dispersion of silver, 60 +/- 5 nm in particle diameter, was synthesized and its stability towards different electrolytes was determined. Furthermore, the surface charge characteristics of silver particles and aluminum beads were evaluated over a broad pH range at different ionic strength. (C) 1999 Elsevier Science B.V. All rights reserved.